Well for mine case, when I redid the way the health system to update only once every few seconds later, compared to every tick, I noticed slight FPS gain. The worst however was with my infinite scrolling background, I couldn't get it to work on the ipad 1 or my old xperia.
It seems like Every tick with any Sprites related movement will cause an issue.
For appMobi, I tried exporting my tests as directcanvas enabled but it turns out black on both the Android devices I tested. It works without it but the performance is very bad. My friends who tested it on Nexus 7 and Note 2 said the performance was at best 20 to 30 ish with noticeable lags.